The invention relates to an apparatus for acquiring and analyzing a blood sample.
Diabetics are instructed that it is important to regularly self-check their blood sugar level. For this purpose, the tip of a lancet must be stuck into the skin of a body part, preferably into the fingertip. A drop of blood exits from the small wound, which is taken up by an analysis element such as a test strip, for example, and subsequently supplied to analysis.
Small automatic handheld devices having an integrated measuring unit and lancets implemented as disposable articles are known in the art. One current development is directed toward an electrically driven apparatus, in which not only the piercing and receiving of a blood sample, but rather also the subsequent analysis up to the output of a measurement result run completely automatically. A supply of disposable lancet test strips is stored in a magazine, so that a number of tests can be performed before the consumable material must be replaced. The advantage of a highly developed apparatus of this type is obvious: while the patient earlier had to carry a piercing aid having a sufficient quantity of lancets and test strips as well as a measuring apparatus and had to handle each of them separately, now a single apparatus, which is conceivably simple to operate, is sufficient to be equipped for monitoring the blood sugar level for days.
It is clear that the design of an apparatus which not only acquires the blood sample, but rather also automatically analyzes it, places a great demand on the designer if all conditions which are currently placed on such a apparatus are to be met. These conditions include, in particular, simple and comfortable operation, ultrahigh reliability, small and light construction, and design simplicity, so that the manufacturing costs may remain acceptable for a mass-produced article. In contrast to simple puncture aids, in which the piercing drive must only drive the lancet, a fully automatic blood sugar test apparatus requires a drive mechanism, which not only drives the lancet, but rather also guides the analysis element to the body part in which piercing was just performed, and then supplies the blood sample to the analysis in a further step. The particular problem is that it makes little sense to move the analysis element in the same manner and on the same path as the lancet, because the analysis element is completely different in form and function from the lancet. A complete movement controller must thus be provided, which is capable of guiding the analysis element to the fixed body part so that it comes into contact with the body part at a different point than the lancet did previously.
Publication No. WO 2008/138 455 A1 describes a puncture system having a device housing, a housing opening for applying a body part, a number of lancets for generating a puncture wound in the body part, sample receiving apparatuses for receiving a bodily fluid sample from the puncture wound, a drive which moves the lancet to generate a puncture wound and subsequently moves a sample receiving apparatus to the puncture wound, and having a coupling part, which couples a lancet and subsequently a sample receiving apparatus to the piercing drive. The system also has a movement controller, which causes the coupling part to reach a final position during a sample receiving movement which is laterally displaced relative to the final position which the coupling part reaches during a puncture movement. Lancets and sample receiving apparatuses are located on a carrier band, which is transported transversely through a gap of the coupling part. The carrier band is bent in the longitudinal direction during the puncture movement, so that the tip of the lancet lifts off of the carrier band. When a sample is taken up, the carrier band is also folded in its longitudinal direction, so that the puncture wound is contacted flatly by the bent-over carrier band and the sample receiving apparatus located thereon, namely a test panel. The movement controller causes a lateral displacement transversely to the puncture direction, so that the puncture wound is contacted flatly by the bent-over test panel. The movement controller accordingly comprises a curved controller having a first control curve for a puncture movement and a second control curve for a sample receiving movement. These control curves run in a guide element, which extends in the puncture direction. A resilient shunt of the control curves determines which one of the control curves a control curve rider travels down. To change over between puncture movement and sample receiving movement, the control curve rider must pass below the shunt, the shunt briefly being raised. This requires force, which must be applied by the piercing drive and which impairs the smooth running and steadiness of the kinematics. Furthermore, it is disadvantageous that the shunt is a component to be produced separately and inserted into the movement controller, which causes additional manufacturing and assembly costs.